The present invention relates to a device and a method for automatically picking up to feed one by one a plurality of cut sheets of paper without jamming or like feed errors.
In particular, the present invention relates firstly to an automatic paper feed device including a stack plate for placing thereon a plurality of cut sheets of paper, a spring member for upwardly biassing the stack plate, a feed roller for forcing one of the cut sheets to slide and a pawl member for separating that one of the cut sheets to be forced to slide from the rest, secondly to a cut sheet cassette for accommodating therein a plurality of cut sheets of paper, the cassette being cooperative with a paper feed system including a pickup roller rotatable in frictional contact with a top sheet of the cut sheets, to thereby pick up the top sheet from the cassette into the system, and thirdly to a cut sheet feeding method for feeding a plurality of cut sheets of paper in a one-by-one picking up manner from a cut sheet cassette into a paper feed system.
As a basic concept, it has been and is typical for such a device, cassette or method to pick up a top sheet from a neat stack of sheets of paper each cut into a predetermined size such as an A3 (297 mm.times.420 mm), A4 (210 mm.times.297 mm) or A5 size (148 mm.times.210 mm) in an A series or a B4 (257 mm .times.364 mm) or B5 (182 mm.times.257 mm) size in a B series in Japan, or a letter (215.9 mm.times.279.4), legal (215.9 mm.times.355.6 mm) or double letter (279.4 mm.times.431.8 mm) size in the United States of America.